New release devlooped/json5@v1.0.0

[kzu]

✨ Implemented enhancements

Json5 Parser

Full JSON5 spec parser for .NET 10+ built entirely on top of the public System.Text.Json API surface.

All JSON5 extensions are supported:

Feature	Example
Unquoted object keys	{ foo: 1 }
Single-quoted strings	'hello'
Multi-line strings (escaped newlines)	'line1\↵line2'
Hexadecimal numbers	0xFF
Leading/trailing decimal points	.5, 2.
Explicit positive sign	+1
Infinity, -Infinity, NaN	Infinity
Single and multi-line comments	// … and /* … */
Trailing commas	[1, 2,]
Additional escape sequences	\v, \0, \xHH
Extended whitespace	Unicode Zs category, BOM

Flexible Output Targets

Parse JSON5 to any System.Text.Json type:

// Parse to JsonNode
JsonNode? node = Json5.Parse(json5String);

// Deserialize to typed object
var config = Json5.Deserialize<AppConfig>(json5String);

// Parse to JsonDocument
using var doc = Json5.ParseDocument(json5String);

// Convert to standard JSON string or bytes
string json = Json5.ToJson(json5String);
byte[] utf8 = Json5.ToUtf8Json(json5Bytes);

// Write directly to Utf8JsonWriter
Json5.WriteTo(json5String, writer);

Auto-Dedent Multi-line Strings

Json5ReaderOptions.AutoDedent automatically strips common leading whitespace from multi-line string values, keeping source readable without polluting string content:

var options = new Json5ReaderOptions { AutoDedent = true };
var node = Json5.Parse("""
    {
        description: '
            This is a multi-line string
            with consistent indentation
            that will be removed.
        '
    }
    """, options);

Configurable Infinity / NaN Handling

Standard JSON has no representation for Infinity and NaN. Control the behavior via Json5ReaderOptions.SpecialNumbers:

Mode	Behavior
AsString (default)	Emits as "Infinity", "-Infinity", or "NaN"
AsNull	Emits as null
Throw	Throws Json5Exception

Json5.Configuration Package

Integrates JSON5 files with Microsoft.Extensions.Configuration, enabling JSON5 anywhere standard JSON config is used — with full support for comments, trailing commas, and unquoted keys:

var config = new ConfigurationBuilder()
    .AddJson5File("appsettings.json5")
    .AddJson5File("appsettings.Development.json5", optional: true, reloadOnChange: true)
    .Build();

Stream-based loading is also supported via AddJson5Stream, and all Json5ReaderOptions (special number handling, max depth, auto-dedent) are accessible through the source action overload.

Full Changelog: https://github.com/devlooped/json5/commits/v1.0.0

Sponsors

The following sponsors made this release possible: @clarius, @MFB-Technologies-Inc, @khamza85, @sandrock, @drivenet, @Keflon, @tbolon, @kfrancis, @unoplatform, @rbnswartz, @jfoshee, @Mrxx99, @eajhnsn1, @Jonathan-Hickey, @KenBonny, @SimonCropp, @agileworks-eu, @arsdragonfly, @vezel-dev, @ChilliCream, @4OTC, @DominicSchell, @adalon, @torutek, @mccaffers, @SeikaLogiciel, @wizardness, @latonz.

Thanks 💜

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